New scientific publication reveals interesting facts on the diet of Egyptian Vultures in the Balkans

14.12.2015

photo: Maria Krumova

New scientific publication of The Return of the Neophron LIFE+ project in the journal Bird Conservation International gives insight on the relationships between diet composition and diversity, and productivity and territory occupancy rate of Egyptian vultures in the Balkans. A prominent threat to European vultures has been sanitary regulations that banned the disposal of livestock carcasses. The resulting decline in easily accessible food have been associated with changes in vulture behaviour and demographic parameters, but still is poorly understood to what extent diet changes are responsible for population declines in vultures.

The Egyptian Vulture is the smallest and most threatened European vulture species and has an opportunistic and diverse diet. In the Balkans, the Egyptian Vulture population is declining more rapidly than elsewhere but there is little information on diet composition and the relationship between diet and demographic parameters to inform conservation management. The present study examined whether Egyptian Vulture population declines in Bulgaria and Greece may have been associated with diet changes that affected breeding productivity. Analyses were based on monitoring of breeding success and 3,237 food remains collected from 143 Egyptian Vulture breeding attempts in the period 2006 - 2013. There was no relationship found between diet diversity or composition and productivity. However, there was a significant relationship between occupancy rate of territories and diet diversity, indicating that occupancy rate decreased with a very diverse or a very narrow diet and a higher proportion of wild animals or a lower proportion of livestock in the diet. There was no temporal change in diet diversity in Bulgaria after admission to the EU in 2007. In conclusion, it is unlikely that diet limitations on reproductive output are a critical threat to Egyptian Vultures on the Balkan Peninsula. The relationship between diet diversity and territory occupancy rate may indicate that adult birds with a very narrow or a very broad diet may be more susceptible to consuming poisoned carcasses, and more information on the effect of diet availability on adult and juvenile survival would be useful to inform and improve conservation management actions.